These twelve data sets are designed to calibrate and increase the accuracy of NASA’s SMAP products. In situ and aircraft data were collected between May and July 2016 in the Carman/Elk region of Manitoba, Canada.

Data set update: Reprocessing is complete for SMAP levels 1-4 data

6 September 2018

The SMAP Data System (SDS) has finished reprocessing the new versions of selected SMAP levels 1-4 data sets. The entire temporal coverage is now available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) for each of the following data sets:

SPL4SMAU, SPL4SMGP, & SPL4SMLM: Land surface modeling system improvements. In addition, data is more CF compliant with the addition of x and y coordinate variables as well as an EASE Grid 2.0 projection mapping variable, which improves interoperability with ArcGIS, QGIS, OPeNDAP, and programmatic access.

AppEEARS offers a simple and efficient way to subset SMAP data sets using spatial, temporal, and layer parameters for both point and area samples. In addition, a step-by-step tutorial for accessing SMAP data in AppEEARS is available for the following five products:

Probe-Based Soil Moisture Data Available for the SMAPVEX15 Campaign

19 March 2018

Field data from the Soil Moisture Active Passive Validation Experiment 2015 (SMAPVEX15) validation campaign are now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

The new data set contains in situ gravimetric and volumetric soil moisture, bulk density, and soil temperature measurements. Visit the product page for details:

Early Release of SMAPVEX16 Manitoba Validation Data

23 February 2018

A variety of field data from the Soil Moisture Active Passive Validation Experiment 2016 Manitoba (SMAPVEX16 Manitoba) validation campaign is now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

Though minimal information is currently available, these data sets are available as part of an early release.Visit the product pages for details:

Early Release of SMAPVEX16 Validation Data

Field data from the Soil Moisture Active Passive Validation Experiment 2016 Manitoba (SMAPVEX16 Manitoba) validation campaign are now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

The new data set, that contains in situ measurements of soil moisture and bulk density, is the first of many for the SMAPVEX16 Manitoba campaign. Though minimal information is presently available, the data set is available as an early release. Visit the product page for details:

L-band radiometer measurements from the SMAP satellite and C-band radar measurements from the European Space Agency (ESA) Copernicus Sentinel-1 satellite are combined to produce high-resolution soil moisture estimates for this product.

The SMAP Science Data System (SDS) began forward processing for the data on 27 October 2017. Data reprocessing from 01 April 2015 to 27 October 2017 will start in mid-November 2017. The data will be made available as they are processed, and registered users will be notified when reprocessing is complete.

These beta-quality data use preliminary algorithms that are still being validated and are therefore subject to uncertainties. The calibrated/validated release of this data set is expected to occur in Spring 2018.

To access all SMAP data and documentation, visit the SMAP Data Web site.

First of SMAPVEX15 Validation Data Sets Now Available

11 September 2017

Field data from the Soil Moisture Active Passive Validation Experiment 2015 (SMAPVEX15) validation campaign are now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

The new data set is the first of many for the SMAPVEX15 campaign and contains brightness temperatures obtained by the Passive Active L-band System (PALS) aircraft instrument. Visit the product page for details:

Updated SMAP Level-4 Products Available

17 July 2017

SMAP Level-4 soil moisture and carbon data have been updated to Version 3 and are available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) via the following product pages:

SMAP observations are now assimilated in Eastern Europe, the Middle East, and East Asia due to expanded coverage of the brightness temperature scaling parameters. The latter are based on two years of SMAP Version 3 brightness temperature observations where the SMOS climatology is unavailable due to RFI.

An improved version of the model-only Nature Run (NRv4.1) simulation is used to derive the brightness temperature scaling parameters, the model soil moisture initial conditions, and the soil moisture climatology.

The SMAP Science Data System (SDS) has reprocessed all affected SMAP Level-1B (L1B), Level-1C (L1C), and Level-2 (L2) radiometer files that had previously been removed. These reprocessed files contain a Composite Release ID (CRID) number of R15060 in the file name. Users are advised to download the replacement data files at their earliest convenience.

The SMAP SDS has corrected the Antenna Azimuth file and regenerated these half-orbits. Users are advised to download the replacement data files at their earliest convenience.

Select Data Files Impacted by SMAP L1B Processing Algorithm Error

15 February 2017

Due to a problem involving the atmospheric correction algorithm used to process SMAP Level-1B (L1B) brightness temperatures, select half-orbit data files contain invalid brightness temperature values. The errors occur infrequently, about one half orbit per month, and affected files have been removed from the following data sets:

The SMAP Science Data System (SDS) team is working to correct the issue in forward processing. Until that time, files will continue to be affected with a frequency of approximately one half orbit per month. NSIDC DAAC will continue to identify and remove all affected files. Files currently affected are documented in a missing files spreadsheet, which will be updated and posted to the following How To article approximately once per month.

Users of L1B brightness temperature data will be able to identify affected files by looking at the first element in tb_lat, tb_lon, or ta_filtered_3. If the element contains the fill value -9999.00, the brightness temperatures stored in tb_v and tb_h will be invalid.

Users of L1C brightness temperature and L2 soil moisture data will need to identify the affected files based on the filenames or orbit numbers documented in the missing files spreadsheet (see the corresponding How To article).

All deleted files will be replaced during the next reprocessing from the beginning of the SMAP mission. Registered users will be notified when reprocessing occurs.

NSIDC Polaris Search and Order being Retired 15 February 2017

2 February 2017

THE NSIDC Polaris Search and Order tool will be retired on 15 February 2017. Please contact NSIDC User Services via email: nsidc@nsidc.org with questions.

Reprocessing Complete for Newly Released SMAP Radiometer Data

31 January 2017

The SMAP Science Data System (SDS) has completed reprocessing of the latest release of SMAP radiometer data products. As a result, the following products are now available from 31 March 2015 to the present:

The new enhanced radiometer products (SPL1CTB_E, SPL2SMP_E, SPL3SMP_E, and SPL3FTP_E) obtain the maximum value from the SMAP radiometer by using Backus-Gilbert optimal interpolation techniques to provide data on a finer (9 km) grid posting than the standard 36 km.

The new radiometer freeze/thaw products (SPL3FTP and SPL3FTP_E) are daily composites of Northern Hemisphere freeze/thaw conditions retrieved by the SMAP radiometer.

As of 07 December 2016, the SMAP Science Data System (SDS) has begun forward processing all products listed above. Data reprocessing from the beginning of the SMAP mission to 07 December 2016 will begin in January 2017. Registered users will be notified when reprocessing is complete.

In addition, the SMAP Level-3 Soil Moisture Radiometer composite file that contains the affected half-orbit scan has been regenerated without half-orbit 08619_D in order to replace the errant file. The new file is:

If you have questions, please contact our User Services Office via e-mail: nsidc@nsidc.org. We apologize for any inconvenience this may cause.

Reprocessing Complete for SMAP Data

21 June 2016

The SMAP Science Data System (SDS) has completed reprocessing of the NASA SMAP Level-1B, -1C, -2, and -3 data products to Validated Version 3. Additionally, SMAP Level-4 products have been reprocessed to Validated Version 2.

During reprocessing, Level-1B, -1C, -2 and -3 data spanning the time period 19 November 2015 to 02 February 2016 were regenerated and replaced due to an issue with a spacecraft ancillary input file. The affected files end with R13080_001.h5. Users who currently have files within this date range may want to download the replacements, as portions of the right edge of the swath near 270° antenna azimuth were erroneously set to fill values.

The SMAP_L1B_TB_01966_A_20150614T231537_R13080_001.h5 file was removed from the SMAP L1B Radiometer Half-Orbit Time-Ordered Brightness Temperatures Data Set because of a problem with the Antenna Azimuth file used to process this half-orbit. The SMAP Science Data System (SDS) is working to correct the Antenna Azimuth file and regenerate these half-orbits. Once we receive the new file, we will let you know.

If you have any questions, please contact our User Services Office via e-mail: nsidc@nsidc.org. We apologize for any inconvenience this may cause you.

The SMAP_L1C_TB_01966_A_20150614T231537_R13080_001.h5 file was removed from the SMAP L1C Radiometer Half-Orbit 36 km EASE-Grid Brightness Temperatures Data Set because of a problem with the Antenna Azimuth file used to process this half-orbit. The SMAP Science Data System (SDS) is working to correct the Antenna Azimuth file and regenerate these half-orbits. Once we receive the new file, we will let you know.

If you have any questions, please contact our User Services Office via e-mail: nsidc@nsidc.org. We apologize for any inconvenience this may cause you.

New Versions of SMAP Products Available

2 May 2016

We are pleased to announce that the SMAP Science Data System (SDS) has begun reprocessing of all data and forward processing of the radiometer data to Validated Version 3 for the Level-1B, -1C, -2, and -3 data products and Validated Version 2 for the Level-4 data products. Registered users will be notified when reprocessing is complete.

The SMAP Science Data System (SDS) has completed reprocessing of NASA SMAP Level-2 and -3 radar and combined radar/radiometer data to Beta Version 2. The following data sets are now available for the full radar time series, 13 April 2015 to 07 July 2015, at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC):

Reprocessing Complete for NASA SMAP Radiometer Data at NSIDC DAAC

9 December 2015

The SMAP Science Data System (SDS) has completed reprocessing of NASA SMAP Level-1, -2, and -3 radiometer data products to Version 2. The following data sets are now available for the full radiometer time series, 31 March 2015 to present, at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC):

Entire SMAP Radiometer and Radar Suite Now Available

4 November 2015

We are pleased to announce that all data from the NASA Soil Moisture Active Passive (SMAP) mission are now available at the National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) and the NASA Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC). The two NASA DAACs jointly manage SMAP science data on behalf of the NASA ESDIS Project.

Currently, Level-2 through Level-4 SMAP data are Beta-quality. Users should note that Beta-quality data use preliminary algorithms that are still being validated and are thus subject to uncertainties. Level-1 SMAP data have been processed to Validated. To access SMAP data and documentation, refer to the SMAP Data page.

As of 30 July 2015, the SMAP Science Data System (SDS) began forward processing Version 1 (beta) radiometer data, which will be made available at the NSIDC DAAC within 12 hours of satellite observation. Reprocessing of data from 31 March 2015 to 29 July 2015 to Version 1 has also begun and data will be made available as they are processed. This reprocessing is expected to be completed in the coming weeks, after which registered data users will receive an announcement.

The beta version (Version 1) of SMAP data sets available at the NSIDC DAAC include:

Data users should be aware that these data use preliminary algorithms that are still being validated and are thus subject to uncertainties. The validated release (Version 2) of all Level-1 data sets is expected to occur in the coming months, along with the beta release of the Level-2, -3, and -4 data sets.

To access all currently available SMAPVEX12 data sets and documentation, visit the SMAP Validation Data Web page.

New SMAPVEX12 Data Available

20 August 2014

New validation field campaign data from the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12) are now available at the NASA National Snow and Ice Data Center
Distributed Active Archive Center (NSIDC DAAC), including:

To access all currently available SMAPVEX12 data and documentation, visit the SMAP Validation Data Web page.

NSIDC Web Site and FTP Server Down for System Maintenance

29 May 2014

From 4:30 p.m. Wednesday, June 04 until noon Friday, June 06 (USA Mountain Time), our Web site and FTP server will be unavailable due to system maintenance. We apologize for any inconvenience this may cause you.

NSIDC Releases Soil Moisture Active Passive (SMAP) Web Site

19 March 2014

We are pleased to announce the release of the official NSIDC Soil Moisture Active Passive (SMAP) Web site. As the SMAP mission progresses, the SMAP Data Web site will provide one convenient location to access SMAP satellite and validation data, tools and services, data version history, news, published research, and other resources.

In addition, seven data sets are currently available from the SMAP Validation Experiment 2012 (SMAPVEX12). To access data and documentation from the SMAPVEX12 campaign, visit the SMAP Validation Data Web page.